The present invention relates to power transmission devices for manually manipulating power transmission systems in small sized vehicles.
In small sized vehicles, such as a motorcycle or the like, a clutch lever is generally utilized for placing the power transmission in its various operating conditions. In such apparatus by pivoting a handle grip the clutch lever is swung to pull a clutch cable to, thereby, interrupt clutch operation. When the operating force applied to the clutch lever is released, the clutch lever is returned to its original position by means of the force of a return spring that is contained in the clutch, whereby the latter is adapted to be returned to its connecting condition.
In such a change-over device, when a large force becomes necessary to return the clutch connection, a return spring having a large spring force is required. Accordingly, when it is desired to manipulate the apparatus to interrupt the clutch, the force of the return spring must be added to the operating force of the manipulating apparatus necessary to operate the interruption of the clutch, whereby the force for operating the interruption of the clutch becomes excessive.
It is to the solution of this problem, therefore, that the present invention is directed.